Telephone receiver



June 29 1926. 1,590,618 H. c. EGERTON TELEPHONE RECEI ER F le pril 5.1922 2 Sheets-Sheet 1 6 t; Q INVENTORE /Z- M- #"ufATTORNEY H. C. EGERTONTELEPHONE RECE]:VER

2 Sheets-Sheet 2 Filed April 5, 1922 $121 WLVVENTOR BY 1 "1 ATTORNEYPatented June 29, 1926 UNITED "STATES HENRY C. EGERTON, OF PASSAIO,

PATENT} OFFICE.

NEW JERSEY; MAY L. EGERTON EXECUTRIX or sun HENRY O. EGERTON, DECEASED.

TELEPHONE aEcEIvER.

Application filed April 5, 1922. Serial No. 549,800.

This invention relates to telephone receivers, but it is well understoodby those skilled in the art that a telephone receiver may also 'be usedas a transmitter and the invention may' therefore be said to relate toboth telephone receivers and transmitters although it is contemplatedthat it will be found of more useful application in connection with thereceivers.

This invention further has reference to that class of telephonereceivers wherein the magnetic flux in the permanent magnets is notaflected by changes in the telephonic currents but in which soft ironpole pieces are employed and the changes in magnetism in the operationof the instrument consists simply in shifting the magnetism from oneportion of the soft iron pole pieces to other portions, the flux throughthe permanent magnets being substantially unchanged.

The main object of the present invention is tosimplify and render moreeflicient instruments of the character described.

'As ancillary to the foregoing object, it.

instrument of Fig. 1, on an enlarged scale and with the horn 'partiallbroken away;

Fig. 3 is a section. on t e line 3-3 of Fig. 2; Fig. 4 is a section onthe line .4-4 of i Fig. 5 is a diagrammatic view showing the relativeconnections and arrangements of the electric coils; and

Fig. 6 is a diagrammatic view showing'a modified arrangement of thewindings.

Referring to the drawings, the apparatus comprises a casing of castbrass having a body 1 from which extend the supporting legs 2 spaced 120from each other and acover 3 having a central opening surrounded curingthcoils.

by the threaded boss 4 to which-the horn 5 is secured. 'Clamped betweenthecover 3 and the flat brass ring 6 is a diaphragm 7 which may be ofmica. Secured against the ring 6 is a permanent magnet 8 of the, horseshoe type. Secured in magnetic relation to the poles of this magnet aretwo flat sort iron pole pieces 9 and 10, the pole piece -9 being clampeddirectly against the magnet while the other is spaced therefrom by sheetiron shims 11. The ring 6, permanent magnet, shims and pole pieces aresecured to the cover byscrews 12. The ends of the pole pieces overlap asshown andthe overlapping ends are bifurcated to form respectively thelegs 13, 14, 15 and 16 on which are respectively mounted-the coils 1718, 19 and 20.

These coils are connected in series as shown in the diagram of Fig. 5and are so wound and relatively connected that the coils on the two'legsof a poleipiece have opposite magneto-motive forces so that upon thepassage of current the magnetism of one of the legs is weakened and theother strengthened. 'The two pole pieces and their coils are soconstructed and connected that .the leg of one pole piece which has itsmagnetism strengthened on passage oi current through the coils is'opposite the leg of the other pole piece which has its magnetismweakened. For instance in the structure shown, upon passage of currentthrough the coils the magnetism of the legs 13 and 16 will be weakened,while the magnetism of the legs 15 and 14 will be strengthened.

The terminals of the loop in which the coils .are connected areconnected to the binding posts '21 and 22 mounted inbutvinsulated fromthe casing, the wires of the telephone circuit being connected with thebinding posts upon the exterior,of the easg. Y It will be seen that-thepole pieces over 'lap each other and their bifurcated ends or legs areadapted to come against the coils on the opposing pole piecesrespectively so. 1 as to hold these coils u on the legs. This forms asecure and simp ified manner of se- 'Between the bifurcated endsbf thepole pieces is mounted an iron' armature 23 which is supported by a flatsprin 25 of non-magnetic material" such as p o'sphor bronze, secured atone end- "to thet fastened to the pole piece 9, and at the other endsecured by soldering, brazing or in other suitable ways to the armature23 at a point substantially midway of its ends. To one end of thisarmature is secured by soldering, brazing or in other suitable ways,

' a bronze wire or operating rod 26., the other objects are where'itengages the sp end of this rod being secured to a diaphragm 7.

It will be observed that the only points of engagement of the armaturewith other and the diaphragm-operating rod 26. .This leaves the systemof diaphragm and connected armature extremely free in its movementandsensitive to variations in the telephonic current. By suitableadjustment the spring may be torsionally stressed so as to place theconnected armature and diaphragm in a desired state of, tension, and theflat spring 25 provides a torsional spring serving to properly positionthe armature and provide the necessary spring opposition to' themovement of the armature under changes in the magnetic action caused bychanges in the telephonic currents. The sprin 25' thus combines in oneelement, where y simplification is realized, and by a single point ofengagement with the armature whereby -sensitiveness of the instrument isincreased, both the'pivotal support of the armature and the spring.pdsitioning means,

therefor. The sprin serves to maintain the armature so that is does nottouch the pole I ieces and is adapted to do this independent- I y of anysupporting efiect of the diaphragm so that the terminal on the diaphragmmay pole pieces can be made any that is sired without considering thesupporting of the armat ure, and

the movable element consisting of the spring, armature and diaphragmshould be of 'such mass and qualit es as to provide the proper naturalfrequency for the instrument.

It will be noted that the spring upon which the armature is" mounted maybe re- -ferred to as of the cantilever type, that is,

havin support at one side of the load only, the :ot er end being free.

It will beseen that the instrument is most simple in construction andthat the receiving mechanism is mounted upon the cover so that it can bereadily removed for in- :pection or repair. Itwill-also be seen thatshimsll serve to' space one of thepolepieces 'from the magnet in anadjustable manner whereb the s acin betweenthe suita ly' a 'usted.

From the foregoing it wil appear that when .the telephonic current inthe coils varies,- the armature willbe given a rotative movement aboutits point of support, the direction in which the armature turnsdepending upon whether the current through the coils is increasing ordecreasing and that any movement from the normal is opposed by-theaction of the spring. The armature, and through it the diaphragm,willtherefore oscillate in response to variation of current in thecoils.

Instead of winding the ole pieces as in e the device of Figs. 1 to 5, te armature ma be wound and the pole pieces, unwoun The instrument may beotherwise in all particulars the same as'that of Fig'slil to 5, themodification being shown in Figii ivherein the bifurcated legs13', 14',15 and'16' are unwound while the armature 23, is provided with a winding27 wound continuously in the same direction and producing one magneticpole at oneend of.the armature and a magnetic pole of opposite olarityat the other end of the armature. Sue end of the armature will thereforebe drawn in onev direction and the ofther endpf the armature in theother direction }y.l 1ereby 'a 'rota'tive movement of the armat'ijireabout its point.

of support is produced, this movement being resisted by the su portingspring. The

armature will there ore vibrate in response to variations of current inthe winding and, if the current reverses the armature will turn from oneside of its normal position to the other.

. While; the invention has been illustrated in what are considered itsbest applications it may ,have other embodiments without departing fromits spirit 'and is not therefore limited to the structures shown in thedrawings.

What I claim is v 1. A telephone instrument comprising in combination apermanent magnet of the horseshoe type, bifurcated. pole pieces of.magnetic material secured in magnetic relation to the poles of saidmagnet respectively and located upon one and the same side of the majorplane of said magnet, an armature rotatively mounted betweensaid poleendof which said armature is rotatively mounted and coils mounted on thelegs of said pole pieces respectively and wound and connected to producerotative movement of said armature on change of current through saidcoils and a diaphragm connected with said armature.

3. A telephone instrument comprising in the major plane of said magnet,an armacombination a permanent 'ma net of the horse shoe type,bifurcated poe pieces of magnetic material secured in magnetic relationto the poles of said magnet respectively and located upon one and thesame side of ture rotatively mounted between said pole pieces and coilsmounted on thelegs of said pole pieces respectively and wound andconnected to produce rotative movement of said armature on change ofcurrent through said coils and a diaphragm connected with said armature,said pole pieces being spaced at diderent distances from said magnet 4.A telephone instrument comprising in combination a permanent ma I et ofthe horse shoe type, bifurcated po e pieces of .magnetic materialsecured in magnetic relation to the poles of said magnet respectively,an armature rotatively mounted between said pole pieces and coilsmounted on the legs of said pole pieces respectively and Wound andconnected to produce rotative movement of said armature on change ofcurrent through said coils and a'- diaphragm connected withsaidarmature, and means .for adjustably spacing said pole pieces inrelation to said magnet.

5. A telephone receiver comprising in combination'a magnet, an armatureadapted to be acted upon by said magnet, coils adapted to affect themovement of said armature, a single spring upomwhich said arma ture ismounted and which provides a pivotal mounting therefor, and adiaphragmconnected with said armature.

6. A telephone receiver comprisingin combination a ma et, an armatureadapted to be acted upon y said magnet, coils adapted to affect. themovement ofsaid armature,

- a single torsional spring adjacent the free end of which said armatureis mounted and which provides a pivotal mounting therefor,

and a diaphragm connected with said armature. I

7. In a telephone I instrument the comv bination with a permanent magnetof the horse shoe type, flat, soft iron, bifurcated polepieces, one ofsaid pole pieces being directly secured to said magnet and means spacingthe other pole piece at a distance from said magnet, a flat springsecured to oneofsaid pole pieces, an armature-secured to the'end of saidspring, a diaphragm, and, means for connecting oneend of said armature,with said diaphragm, and "coils .mounted respectively upon the legs ofsaid pole pieces, said coils being wound and connected to producerotative movement of said armature upon change of current through saidcoils.

8. A telephone instrument comprising in combination a magnet, polepieces for said magnet and coils on said pole pieces, said" pole' piecesrespectively being" adapted to abut against the coils of their opposingpole pieces to prevent the coils from sliding 0!? their respective polepieces, an armature between said pole-pieces and a diaphragm connectedwith said armature.

9. A telephone instrument comprising in combination a magnet, polepieces for said magnet, said pole pieces overlapping each other andcoils on said pole pieces, said pole pieces respectively being adaptedto abut against the coils of their opposing. pole/ pieces to prevent thecoils from sliding olf their respective pole pieces, an armature''betw'een said pole ieces and a diaphragm connected with said armature.

10. A telephone instrument comprising in combination a casingcomprisinga body por tion and a cover, adiaphragm, a permanent magnetand fiat, bifurcatedpole pieces of .soft iron secured inma gneticrelation tdsa/id magnet and upon one and the same side of the majorplane thereof, said pole ieces being spaced at ,difl'erent'distancesom'said magnet, coils upon said pole pieces, a torsional spring securedto one of said pole pieces, an armature between said pole pieces andmounted upon said spring and means connecting said armature with saiddiaphragm, said magnet, pole pieces, coils, spring, armature and diaphragmbeing mounted upon said cover.

11. A telephone receiver comprising-a flat 12. Intelephone receiver asubstantiallyflat horseshoe permanent magnet, a substantially flat facedbifurcated pole piece mounted on each end of said magnet, a substan;tiallyv flat armature, a single torsional spring adjacent the free endof which said armature is mounted and a diaphragm connected to one endof said armature.

13. In a telephone 'receivera substantially flat'horseshoe ermanentmagnet, a substantially fiat faced ed on each end of said magnet, asubstan tially flat armature held in operative relation between saidpole pieces by a single, cantibifurcated pole piece mountlever type,torsional spring whichis suplported on one of said pole pieces and whichasits major plane substantially atvrightangles to the plane of the polepieces and a diaphragm connected to one end of said armature.

14. In a telephone receiver a substantially fl t horseshoe permanentmagnet, flat pole pieces associated with each end of said magnet, said-pole pieces each being mounted on the same side of said magnet, a flatarmaangles to the plane of said pole pieces, said ture in operativerelation to and mounfd bespring being supported by one of said poletween the ends of said pole pieces, the maior pieces. p planes of all ofsaid members being paral e1, In testimony whereof I have signed this 5said armature being maintained in operative specification this first dayof April, 1922.

relation to said pole pieces by a singletorsional spring whose majorplane is at right w I 'ZHENRY C. EGERTON.

